What is the default disturbance recovery period to return ACE to 0 following a disturbance?

The default disturbance recovery period to return Area Control Error (ACE) to zero following a disturbance is set at 15 minutes. This timeframe is significant because returning to a normal operating state after a disturbance is critical for maintaining system reliability. In the context of power system operations, the restoration of ACE to zero is essential to ensure that frequency and power balance are maintained across the grid.

During this 15-minute recovery period, operators actively work to stabilize the system by adjusting generation outputs and loads as necessary. This can involve fine-tuning resources to balance the supply and demand effectively. Adhering to the 15-minute standard supports coordinated efforts among reliability coordinators, balancing authorities, and transmission operators, facilitating a uniform approach to managing disturbances across the interconnected grid.

The other options suggest longer timeframes for recovery, which may not reflect the operational expectations for prompt responses to disturbances in the power system. Keeping the recovery period concise helps mitigate risks associated with prolonged imbalances that could lead to larger, more significant reliability issues.